To add to the interesting threads on hoses, here's one from someone with no physics knowledge. Please be patient with this basic question!
If you open your hose valve and press the trigger on the nozzle of the hoze, I understand that thanks to the pressure of gravity from the water tower or what have you, water escapes at great velocity.
If you close your hose valve, and then go press the trigger, water still escapes at great velocity.
Why doesn't it dribble out (till the very end)? Where is the pressure coming from? Isn't the water just sitting in the hose between the valve and the nozzle?